Mineral fiber insulation batts coated with kraft paper and the like are old and well-known. Examples of mineral fiber include fiberglass, rock wool, etc. Typically, the base mineral fiber insulation batt is processed along an endless conveyor system and a sheet(s) of kraft paper is adhered to at least one surface of the insulation batt. The resulting batts, coated with kraft paper, are typically used for insulating vertical wall cavities and the like.
Unfortunately, such batts suffer from the following problems: (i) they lack durability and are susceptible to damage such as tearing at job sites; (ii) they tend to allow dust to be generated therefrom; (iii) paper burns; (iv) their aesthetic appearance is less than desirable to many in the trade; and (v) cost of paper. Accordingly, there exists a need in the art to improve upon the above-listed drawbacks of kraft paper coated mineral fiber batts.
It is also known to apply polyethylene and polypropylene films to batts. For example, see U.S. Pat. Nos. 5,318,644; 5,362,539; and 5,277,955.
U.S. Pat. No. 5,362,539 discloses a polyethylene or polypropylene film applied to an insulation batt. Either an adhesive, Velcro.TM., or heat sealing is used to adhere the film to the mineral fiber core. Unfortunately, with respect to use of an adhesive or Velcro.TM. to attach the film to the core, these represent multi-step adhering processes for coating the batt with film, which are both undesirable and inefficient. Additionally, such batts are susceptible to cold-crack at temperatures which range down to about -65.degree. F. Cold-crack often occurs when hot melt adhesives and the like are utilized to adhere laminants together, this often resulting in the laminates prematurely separating or delaminating. With respect to heat sealing the polyethylene or polypropylene to the mineral fiber core, this has been found by the instant inventors to represent a less than sufficient attachment of the film to the core. For example, the instant inventors have found that when commercial attempts to laminate polymer films to a fiberglass batt have been made, the surface strength of the lamination is sometimes incapable of maintaining the weight of the fiberglass in certain instances and often results in de-lamination. Furthermore, complex equipment is required to manufacture such poly film-coated batts, which is not cost effective.
U.S. Pat. No. 5,277,955 discloses a mineral fiber batt to which a polyethylene layer is applied. The polyethylene layer may be heated for the purpose of joining the film to the mineral batt. As discussed above, and as apparently recognized in the '955 patent, this may not result in an adequate attachment of the film to the batt. Accordingly, the disclosure of the '955 patent suffers from the same problems as those discussed above regarding the '539 patent.
U.S. Pat. No. 5,318,644 discloses a method and apparatus for making an insulation assembly, wherein a pair of polyethylene layers are utilized to encapsulate a mineral fiber batt. Unfortunately, the system of the '644 patent suffers from the same problems that are discussed above regarding the '955 and '539 patents.
In view of the above, it will be clear to those of skill in the art that there exists a need in the art for an improved mineral fiber insulation batt, and corresponding method and apparatus for manufacturing same, which is efficient and cost effective to manufacture, is easy to handle, is less susceptible to cold-crack, it is aesthetically attractive, and reduces generation of dust. It is a purpose of this invention to fulfill the above-described needs in the art as well as other needs which will become apparent to the skilled artisan upon review of this disclosure.